Flutuação populacional de Melanaphis spp. em ambiente de cerrado no ano de 2021

Abstract

The introduction of Melanaphis sorghi (Theobald) to Brazil was a very important milestone for agriculture because the species is considered a sorghum pest due to its sap-sucking and reduction of photosynthesis. This necessitated studies to understand the population fluctuations of this aphid to aid in its management. The objective of this study was to analyze the influence of meteorological factors (precipitation, humidity and maximum, average, and minimum temperatures) on the population fluctuations of Melanaphis spp. Weekly collections were carried out for an 11-month period, beginning on February 10, 2021, and ending on December 29, 2021, at the Capim Branco Experimental Farm of the Federal University of Uberlândia (UFU). Collections were made once a week in four yellow trays (Moericke-type traps). These were then screened, separating all aphids, and then identified based on the morphological characteristics of the winged insects. Since it is not possible to separate individuals of M. sorghi and Melanaphis sacchari (Zehntner) by taxonomic methods, identification was made at the genus level (Melanaphis van der Goot), considering that both species may have occurred in the samples. The trays were located in an area with spontaneous vegetation, surrounded by areas cultivated with corn, soybean, sorghum, and cotton over time. Pearson's correlation analysis and graphical analysis were performed between the meteorological data and the average population of Melanaphis spp. There was no significant correlation between the analyzed meteorological factors and the winged population of M. sorghi. However, graphical analysis revealed that the aphid outbreak (159.5 individuals) occurred during the dry season, warm temperature (averaging 23.78°C), and low relative humidity (57.49%). With the combination of meteorological factors that favored the Melanaphis spp. outbreak in the present study, it is expected that colonization by these aphid species will be increased in sorghum and/or sugarcane crops.